The need for a tamper evident means on the doors, hoods and trunk lids of motor vehicles results from the fact that expensive components stored therein are sometimes found missing when the vehicle is delivered to the dealership. The problem attendant to preventive measures is pinpointing the stage of assembly or delivery when the tampering occurred.
The institution of controls for prevention involves frequent, repetitive inspections with concomitant delay and expense. Mechanical inspection devices are limited since vehicle deck lids and doors are normally closed and the removal of components like sound systems, spare tires or engine components is not readily discernable upon reclosure thereof.
Various devices have heretofore been developed to solve the problem. U.S. Pat. No. 1,006,087 to Hertzberg (Oct. 1911) discloses a shaving cup with a tamper-evident seal. There is a sealing strip for positioning around the cup at the junction of the cup and the cover. This sealing strip has an adhesive on it, adhering the strip to the cup and cover. Until the strip is broken, the shaving cup cannot be opened. Indicia printed on the strip indicate whether the seal has been broken. This patent shows the long-felt need for tamper-resistant seals.
U.S. Pat. No. 2,254,936 to Dick (Sept. 1941) discloses a package for containing and dispensing a fluid, in this case, a brake fluid. The package has a band 7 that has a tab 8 for aiding in tearing off the band.
U.S. Pat. No. 3,854,581 to Jones, Jr. (Dec. 1974) discloses the use of a pressure sensitive adhesive, (PSA), with a polymeric supporting material to provide a tamper-evident seal. The preferred support material is a polyolefin, particularly a polypropylene that is foamed and stretched so that it is uniaxially oriented to be weaker in the longitudinal direction.
U.S. Pat. No. 4,432,462 to Newkirk (Feb. 1984) discloses a completely different method of evidencing tampering. The tampering indicator has a fluid-filled reservoir and a chemical indicator strip, used with a receptacle having a cap Although the reservoir and the indicator strip are in communication with each other, the path is blocked until the cap is removed from the receptacle, the path is unblocked and the fluid can reach the indicator strip, where it causes a reaction to occur, showing the characteristic color that indicates tampering has occurred.
U.S. Pat. No. 4,468,811 to Shaw (Aug. 1984) discloses a tamper-evident closure for a bag. The closure consists of opposed webs 12 and 14. One of the webs has a flap 26 that has a pressure sensitive adhesive, (PSA), on it so that the flap can be sealed onto the other web as well as itself when it is folded over. The flap also has a transverse perforation or weakening 30 so that it will rupture before the PSA adhering to each of the respective webs does.
U.S. Pat. No. 4,555,037 to Rhees (Nov. 1985) discloses a tamper-evident inner seal for a container having a circular opening. The seal material is adhered around the circumference of the opening, and a circular pattern of perforations 48 around the inner portion of the seal provides a weakened point for opening the seal.
U.S. Pat. No. 4,679,693 to Forman (July 1987) discloses a resealable label for a container that uses a PSA on the label as well as a perforated or scored area.
U.S. Pat. No. 4,941,196 to Edelman (July 1990) discloses a closure flap for a bag that readily exhibits tampering with the flap after sealing. If the seal has been tampered with, a printed security pattern becomes visible through the clear seal, which is another method of demonstrating tampering.
U.S. Pat. No. 4,944,603 to Cornish (July 1990) discloses a resealable package with an encompassing tamper-evident band. This band 20 extends across an opening 18 in the package, as shown in FIG. 1, so that the opening cannot be opened without disrupting the band. The band has a transverse perforation or weakening 23, and the band is adhered to the package on either side of the opening by adhesive spot bonds 21. The claim requires at least lines of perforation (See Column 4, Line 64).
U.S. Pat. No. 4,961,503 (Oct. 1990) and U.S. Pat. No. 5,046,621 (Sept. 1991), both to Bell, disclose a tamper-evident notched sealing bag. The novelty appears to be a very strong PSA that will crinkle the flap if someone attempts to open the flap.
U.S. Pat. No. 5,141,150 to Plaessmann (Aug. 1992) discloses a pouring spout having a tamper-evident covering label thereon. The covering label 22 is a frangible sheet having an adhesive portion 24 and an adhesive-free portion 30. A perforation 34 divides the label into upper and lower portions. When the adhesive-free portion is grasped, the perforation tears, exposing the spout, which may then be opened. Since the adhesive portions occur on each side of the transverse perforation and the perforation will preferentially tear rather than have the adhesive yield.
None of the foregoing devices have application for preventing tampering with motor vehicles from the first stage of assembly line construction to dealer's acceptance. There is, therefore, a need for a tamper-evident security seal which would efficiently provide immediate, ostensible evidence of tampering.